/**
 * Created by Administrator on 2016/4/2.
 */
public class StackTraceDemo2{
    public static void main(String[] args){
        try{
            c();
        }catch(NullPointerException ex){
            ex.printStackTrace();
        }
    }
    static void c(){
        try{
            b();
        }catch(NullPointerException ex){
            ex.printStackTrace();
            throw ex;
        }
    }
    static void b(){
        a();
    }
    static String a(){
        String text=null;
        return text.toUpperCase();
    }
}